ST_AddMeasure-ApsaraDB RDS(RDS)-阿里云帮助中心

Interpolates m-coordinate values linearly along a geometry object within a specified measure range, and returns the updated geometry.

Syntax

geometry ST_AddMeasure(geometry geomMline, float8 measureStart, float8 measureEnd)

Parameter	Type	Description
`geomMline`	`geometry`	The LineString object that you want to specify.
`measureStart`	`float8`	The minimum m coordinate that is allowed.
`measureEnd`	`float8`	The maximum m coordinate that is allowed.

This function supports only MultiLineString objects.
If the input geometry has no m dimension, an m dimension is added.
If the input geometry already has an m dimension, the existing m-coordinate values are overwritten.
3D geometries are supported. The z-coordinate values are preserved.

Add m-coordinate values ranging from 1 to 2 to a 2D LineString:

SELECT ST_AsText(ST_AddMeasure('LINESTRING(1 0, 2 0)'::geometry,1,2));

Output:

         st_astext
----------------------------
 LINESTRING M (1 0 1,2 0 2)
(1 row)